/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license agreements. See the NOTICE file distributed with this work for additional information regarding copyright ownership. The ASF licenses this file to You under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
 */
package com.opensource.dbhelp.dbutils.handlers;

import java.sql.ResultSet;
import java.sql.SQLException;
import java.util.ArrayList;
import java.util.List;

import com.opensource.dbhelp.dbutils.ResultSetHandler;

/**
 * Abstract class that simplify development of <code>ResultSetHandler</code> classes that convert <code>ResultSet</code> into <code>List</code>.
 *
 * @param <T>
 *            the target List generic type
 * @see com.opensource.dbhelp.dbutils.ResultSetHandler
 */
public abstract class AbstractListHandler<T> implements ResultSetHandler<List<T>> {

	/**
	 * Whole <code>ResultSet</code> handler. It produce <code>List</code> as result. To convert individual rows into Java objects it uses <code>handleRow(ResultSet)</code> method.
	 *
	 * @see #handleRow(java.sql.ResultSet)
	 * @param rs
	 *            <code>ResultSet</code> to process.
	 * @return a list of all rows in the result set
	 * @throws java.sql.SQLException
	 *             error occurs
	 */
	@Override
	public List<T> handle(ResultSet rs) throws SQLException {
		List<T> rows = new ArrayList<T>();
		while (rs.next()) {
			rows.add(this.handleRow(rs));
		}
		return rows;
	}

	/**
	 * Row handler. Method converts current row into some Java object.
	 *
	 * @param rs
	 *            <code>ResultSet</code> to process.
	 * @return row processing result
	 * @throws java.sql.SQLException
	 *             error occurs
	 */
	protected abstract T handleRow(ResultSet rs) throws SQLException;
}